The subject matter described herein generally relates to controlling an environment of a fuel tank and, more particularly, to systems and methods for curing a sealant within a fuel tank of an aircraft.
During an assembly of a fuel tank of an aircraft, a sealant is applied within an interior of the fuel tank to seal the fuel tank and keep it from leaking. After a sealant is applied, the sealant must be cured before the assembly of the fuel tank is complete. Two of the main factors that affect the curing process are temperature and relative humidity (RH) within the fuel tank. Generally speaking, as the temperature and/or RH increase, the time it takes to cure a sealant decreases. As a result, curing times of a sealant may vary based on time of year and/or factory environment. For example, during summer, a sealant may take up to 10% longer than normal to cure due to low RH and uneven air distribution. During winter, a sealant may take up to twice as long to cure due to low temperatures, low RH, and uneven air distribution.
However, while the sealant is curing within the fuel tank, mechanics may be required to work for extended periods of time inside the fuel tank. Thus, for the safety of the mechanics working therein, the environment of the fuel tank must be monitored such that the temperature and/or RH are maintained at acceptable levels. For example, if the temperature within the fuel tank exceeds 79° F., the mechanics are required to exit the fuel tank for safety purposes. Thus, while the sealant may cure more quickly as the temperature increases, the mechanics are unable to continue working in an environment that is above 79° F.
Further, chemicals such as isopropanol (IPA) and methyl propyl ketone (MPK) used during the assembly of a fuel tank require the fuel tank to be heavily ventilated in order to create an environment inside the fuel tank that is suitable/safe for mechanics working therein. However, current systems and methods of ventilating a fuel tank create large variances in temperature, RH levels, and air circulation throughout the fuel tank. As a result, curing times of a sealant are non-uniform throughout the fuel tank and dead spots created by poor circulation enable a pooling effect of volatile organic compounds (VOCs). This not only creates discomfort for the mechanics working within the fuel tank, but can lead to such a dangerous environment that prohibits the mechanics to work within the fuel tank.
Therefore, there is a need in the field of curing sealants within fuel tanks for a system and method that control an environment of a fuel tank such that a curing time of a sealant, a mechanics discomfort, VOC pooling, and variances between temperature/RH levels throughout the fuel tank are reduced.